1. Field of the Invention
This invention generally relates to a dental drill. More specifically, the present invention relates to a dental drill having a shaft and a cutting portion with cutting edges.
2. Background Information
In the dental field, drills are commonly used, among other things, for drilling out fillings in teeth. In many cases the fillings consist of amalgam which contains a high amount of mercury. When such fillings are drilled out, minute mercury-containing particles or pieces are formed. These minute mercury-containing particles or pieces may be swallowed by the patient, as well as mercury vapors which may be inhaled by the patient and/or the dentist, possibly resulting in mercury poisoning. Hence, in the case of conventionally used drills, there exists a risk that patients and dentists might be exposed to a high mercury load.
Moreover, as for dental preparatory techniques, it is important that as little as possible of the healthy tooth material be removed while the fillings are being drilled. As a result, the tooth is just damaged to the necessary degree on the one hand and the subsequent treatment of the tooth is facilitated on the other hand, since the existing healthy tooth material remains to a maximum degree.
German Publication DE 195 02 030 A1 already discloses a drill for metal working in which two main cutting edges are provided at the front side converge in the central axis and pass into two secondary cutting edges of a cutting portion on their radially outer end portions. The cutting portion does not comprise any additional cutting edges.
In view of the above, there exists a need for a dental drill which overcomes the above mentioned problems in the prior art. This invention addresses this need in the prior art as well as other needs, which will become apparent to those skilled in the art from this disclosure.